Electronics manufacturer Foxconn maintains that workers making iPhones at a Chinese factory did not strike on Friday and that production wasn't affected, according to published reports.

Foxconn's statement contradicts a labor rights group, which said that between 3,000 and 4,000 workers at Foxconn's Zhengzhou factory went on strike on Friday afternoon. According to China Labor Watch, based in New York, the workers' actions brought some iPhone production lines to a halt.

However, Foxconn on Saturday said that no such thing happened, and that instead there were two "isolated" disputes between workers and supervisors earlier in the week that didn't affect production, according to reports.

In an update to its Friday statement, China Labor Watch reiterated that the workers in question did go on strike, but that they returned to work on Saturday. The group said that China celebrates a national holiday between October 1 and October 8, and that Foxconn required that workers in the Zhengzhou factory work during this period to meet iPhone 5 production goals, but that workers from the quality control line walked off the job on Friday.

On Friday, China Labor Watch had said that the workers were also angry over stricter quality control requirements for the manufacturing of the iPhone 5.

A plant worker told IDG News Service on Friday that heightened quality controls are resulting in an increased number of intercepted products, leading to missed volume targets and increased workplace tension.

"As a result, there was conflict and they beat our people," said the worker, who declined to give her name but said she works in the "quality department."

She claimed workers at the plant were beaten twice last week for similar reasons. "Our long-suppressed anger erupted and we went on strike," she said, communicating via Tencent Weibo, a Chinese Twitter-like service.

Her account is consistent with China Labor Watch's report that a fight broke out between workers and quality-control inspectors on Friday, resulting in some injuries and hospitalizations.